A clinical case of successful surgical treatment of a patient with chronic pancreatitis, complicated by suppuration of a postnecrotic cyst and the formation of a cysto-gastric fistula. As a result of the conservative and minimally invasive treatment, the pseudocyst was drained, and the cystogastric fistula was closed. The staged treatment was completed by resection of the head of the pancreas with the formation of an anastomosis.